diff --git a/c/containers/lhms2v.c b/c/containers/lhms2v.c
index 0297f743c..a95cc90df 100644
--- a/c/containers/lhms2v.c
+++ b/c/containers/lhms2v.c
@@ -85,6 +85,7 @@ void lhms2v_free(lhms2v_t* pmap) {
 	if (pmap == NULL)
 		return;
 	free(pmap->entries);
+	free(pmap->states);
 	pmap->entries      = NULL;
 	pmap->num_occupied = 0;
 	pmap->num_freed    = 0;
diff --git a/c/containers/lhmsi.c b/c/containers/lhmsi.c
index ffb752cc8..1d64b9c6e 100644
--- a/c/containers/lhmsi.c
+++ b/c/containers/lhmsi.c
@@ -88,6 +88,7 @@ void lhmsi_free(lhmsi_t* pmap) {
 		free(pe->key);
 	}
 	free(pmap->entries);
+	free(pmap->states);
 	pmap->entries      = NULL;
 	pmap->num_occupied = 0;
 	pmap->num_freed    = 0;
diff --git a/c/containers/lhmslv.c b/c/containers/lhmslv.c
index 442b29c57..a55513818 100644
--- a/c/containers/lhmslv.c
+++ b/c/containers/lhmslv.c
@@ -87,6 +87,7 @@ void lhmslv_free(lhmslv_t* pmap) {
 	for (lhmslve_t* pe = pmap->phead; pe != NULL; pe = pe->pnext)
 		slls_free(pe->key);
 	free(pmap->entries);
+	free(pmap->states);
 	pmap->entries      = NULL;
 	pmap->num_occupied = 0;
 	pmap->num_freed    = 0;
diff --git a/c/containers/lhmss.c b/c/containers/lhmss.c
index 657f67366..f672b2b99 100644
--- a/c/containers/lhmss.c
+++ b/c/containers/lhmss.c
@@ -88,6 +88,7 @@ void lhmss_free(lhmss_t* pmap) {
 		free(pe->value);
 	}
 	free(pmap->entries);
+	free(pmap->states);
 	pmap->entries      = NULL;
 	pmap->num_occupied = 0;
 	pmap->num_freed    = 0;
diff --git a/c/containers/lhmsv.c b/c/containers/lhmsv.c
index 309255746..a72849f3e 100644
--- a/c/containers/lhmsv.c
+++ b/c/containers/lhmsv.c
@@ -81,6 +81,7 @@ void lhmsv_free(lhmsv_t* pmap) {
 		free(pe->key);
 	}
 	free(pmap->entries);
+	free(pmap->states);
 	pmap->entries      = NULL;
 	pmap->num_occupied = 0;
 	pmap->num_freed    = 0;
diff --git a/c/mapping/lrec_evaluators.c b/c/mapping/lrec_evaluators.c
index fa2f8ecd1..306dd480a 100644
--- a/c/mapping/lrec_evaluators.c
+++ b/c/mapping/lrec_evaluators.c
@@ -762,8 +762,10 @@ mv_t lrec_evaluator_x_ns_func(lrec_t* prec, context_t* pctx, void* pvstate) {
 
 	mv_t val2 = pstate->parg2->pprocess_func(prec, pctx, pstate->parg2->pvstate);
 	NULL_OR_ERROR_OUT(val2);
-	if (val2.type != MT_STRING)
+	if (val2.type != MT_STRING) {
+		mv_free(&val1);
 		return MV_ERROR;
+	}
 
 	return pstate->pfunc(&val1, &val2);
 }
@@ -932,13 +934,18 @@ mv_t lrec_evaluator_s_sss_func(lrec_t* prec, context_t* pctx, void* pvstate) {
 
 	mv_t val2 = pstate->parg2->pprocess_func(prec, pctx, pstate->parg2->pvstate);
 	NULL_OR_ERROR_OUT(val2);
-	if (val2.type != MT_STRING)
+	if (val2.type != MT_STRING) {
+		mv_free(&val1);
 		return MV_ERROR;
+	}
 
 	mv_t val3 = pstate->parg3->pprocess_func(prec, pctx, pstate->parg3->pvstate);
 	NULL_OR_ERROR_OUT(val3);
-	if (val3.type != MT_STRING)
+	if (val3.type != MT_STRING) {
+		mv_free(&val1);
+		mv_free(&val2);
 		return MV_ERROR;
+	}
 
 	return pstate->pfunc(&val1, &val2, &val3);
 }
@@ -985,8 +992,10 @@ mv_t lrec_evaluator_x_srs_func(lrec_t* prec, context_t* pctx, void* pvstate) {
 
 	mv_t val3 = pstate->parg3->pprocess_func(prec, pctx, pstate->parg3->pvstate);
 	NULL_OR_ERROR_OUT(val3);
-	if (val3.type != MT_STRING)
+	if (val3.type != MT_STRING) {
+		mv_free(&val1);
 		return MV_ERROR;
+	}
 
 	return pstate->pfunc(&val1, &pstate->regex, pstate->psb, &val3);
 }
diff --git a/c/mapping/mapper_uniq.c b/c/mapping/mapper_uniq.c
index aebbd337a..4ecf69947 100644
--- a/c/mapping/mapper_uniq.c
+++ b/c/mapping/mapper_uniq.c
@@ -227,7 +227,6 @@ static sllv_t* mapper_uniq_process_no_counts(lrec_t* pinrec, context_t* pctx, vo
 
 	slls_t* pgroup_by_field_values = mlr_selected_values_from_record(pinrec, pstate->pgroup_by_field_names);
 	if (pgroup_by_field_values == NULL) {
-		slls_free(pgroup_by_field_values);
 		return NULL;
 	}
 
diff --git a/c/todo.txt b/c/todo.txt
index 278e4c1ad..6a7799675 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -23,6 +23,7 @@ TOP OF LIST
   - track-origins?
   - xxxes
   - more rid of "double" in fcn names
+  - mv_format_val in case string is allocated. modify semantics to nullify the arg??
 * profile new streqn vs. strncmp ...
 * mixed-format joins ...
 * stats1 handle empty-key nulls? stats2? step? top? etc ...